1. Field of the Invention
The invention relates to a dispensing closure for chemical and pharmaceutical substances, particularly narcotic liquids, narcotic gases, or the like, said closure comprising a sealing or closure cap which is applied to the opening of the substance-dispensing container, and further comprising of an adapter piece with code markings, to establish a joint between the adapter and a receiving structure on the container being filled. The receiving structure has corresponding markings. The sealing cap and the adapter are interconnected by a flexible, liquid-passing tube which opens into a transverse bore hole passage for liquid, and by a flexible air-delivery tube which opens into a transverse air admission bore hole.
2. Description of the Related Art
In a known dispensing closure, the sealing cap and the adapter piece are each provided with a tube nipple over which a piece of flexible tubing is pushed. This flexible tubing is secured to each of the nipples by a respective ring clamp to prevent it from being pulled off. The adapter piece is provided with a blind hole, and with two transverse holes of different diameters which extend into the blind hole. The larger diameter transverse hole serves as a liquid passage, and the smaller diameter transverse hole serves to hold the flexible ventilation tube in place, which tube extends through the entire length of the dispensing closure and is pulled into the smaller transverse hole by bending said tube around. The known dispensing closure is very costly to manufacture and assemble. It has at least six parts, some of which are metal and some plastic. It is costly to assembly because one must push the ends of the flexible tubing over the tube nipples, apply the ring clamps, and laboriously install or "thread-in" the flexible air-delivery tube, all separate, labor-intensive steps. In particular, there are substantial problems presented in passing the air-delivery tube around the 90.degree. bend inside the narrow liquid passage.